1. Technical Field
The subject invention relates to a motion transmitting remote control assembly of the type for transmitting motion along a curved path by a flexible motion transmitting core element movably supported within a flexible conduit. More specifically, the subject invention relates to an assembly including an adjustment member for adjusting the length of the core element or conduit.
2. Description of the Related Art
Remote control assemblies including an adjustment member for adjusting the position of a conduit or core element are well known in the art. Such remote control assemblies generally include a core element slidably disposed within a flexible conduit. The ends of the core element extend from the ends of the conduit and are adapted to interconnect a control member and an actuator for transmitting forces therebetween. It is frequently desirable to adjust the effective length of the core element or conduit between the control member and the actuator after the assembly has been interconnected therebetween. For example, during installation of such an assembly in a vehicle, the effective length of the core element between the control member and the actuator often needs adjustment due to variances in dimensional specifications of different vehicles. Accordingly, to effect such an adjustment, the core element must be routed along a more or less direct path, between the control member and the actuator, to lengthen or shorten its effective length therebetween. In order to make such an adjustment, assemblies include adjustment members. Typical adjustment members include three essential components; a first member secured to either the conduit or core element, a second member moveable relative to the first member and secured to either a control member, actuator, or fitting and a third member for selectively interlocking the first and second members together thereby preventing movement therebetween.
An assembly for accomplishing such an adjustment is shown in U.S. Pat. No. 4,177,691 in the name of Fillmore and assigned to the assignee of the subject invention. The Fillmore '691 patent discloses an assembly with an adjustment member including a first member secured to the end of the conduit with adjustment teeth disposed along the sides thereof. The first member extends through a passageway in a support member which is adapted for attachment to a support structure. A locking member, having locking teeth thereon, is movable between engaged and disengaged positions for selectively engaging the locking teeth with the adjustment teeth disposed on the first member thereby preventing movement between the first member and the support member.
U.S. Pat. No. 3,572,159 granted Mar. 23, 1971 at August E. Tschanz and assigned to the assignee of the subject invention, discloses an assembly similar to that just described. However, the Tschanz '159 assembly includes a locking member having a circular opening with threads therein for engaging a circular first member. Although this circular arrangement allows for relative rotation between the conduit and the second member, such rotation in fact changes the effective length of adjustment of the assembly. That is, by rotating the conduit relative to the second member, the circular first member actually "threads" or "screws" longitudinally through the circular threads of the locking member. Consequently, the rotation of the conduit is obtained at the expense of changing the adjustment of the conduit and core element. Additionally, when the locking member moves slightly from its fully engaged position, large portions of its circular threads become disengaged from the adjustment member, thereby decreasing the holding power of the locking member upon the adjustment member. Partial disengagement is particularly common in vehicular applications due to the jarring and vibration most assemblies are exposed to.
Due to the precision required in many motion transmitting remote control applications, highly accurate adjustments are often needed. Accordingly, in such applications it becomes necessary to utilize adjustment members capable of extremely fine adjustments. Unfortunately, prior art adjustment members are limited by the thickness of their adjustment teeth. That is, the incremental adjustment of the core element is limited by the thickness of the adjustment teeth. While thinner adjustment teeth permit finer adjustment, they also are weak and provide insufficient holding strength.